The mobile air conditioning systems in vehicles, typically referred to by the English term “Mobile Air Conditioning System/MAC”, comprise connection valves on the low pressure side and on the high pressure side. The air conditioning systems are pressure tested, evacuated, and filled using these connection valves. Furthermore, these valves allow necessary maintenance operations in the further life cycle of the air conditioning system. The geometrical contours of the connection valves are of different designs. This prevents confusion between the high pressure side with the low pressure side and at the same time ensures that only the respective approved refrigerant is filled into the air conditioning system. Prevention of mix-ups with respect to filling with the wrong refrigerant is particularly required on the side of the high-pressure adapter, since it is used to fill most air conditioning systems.
Various devices for filling containers, circuits, and similar components of vehicles with fuel, lubricants, refrigerants, and other operating fluids are known from prior art, for example from U.S. Pat. No. 6,848,670 B2, U.S. 2007 / 0 256 742 A1, or WO 2007/106 486 A1. In particular, the connection geometries of the filling system and the assembly to be filled must be matched to one another.
The geometries of the various connection valves on air conditioning systems are defined in the internationally binding SAE standard J 639. The exact dimensions and differences of the connection valves for the media R134a and R1234yf that are typically used as refrigerants can be seen in FIG. 1.
The air conditioning systems are filled with refrigerant for the first time during final vehicle assembly. This process of initial filling is performed using filling systems that need a high pressure and a low-pressure adapter for each type of air conditioning system to be filled. Where two different air conditioning systems are installed in final vehicle assembly, which also must be filled with different refrigerants (e.g. R134a and R1234yf), a total of four adapters are required at the associated filling system. Note that the filling system uses different components for the different refrigerants. Such designs in which the filling system is divided according to the media used increase the investment required, incur costs for later maintenance and require considerable installation space at the final assembly location, which limits the space available for potential extensions of the filling system. FIG. 2 shows the general structure of a filling system of such a design with media separation according to prior art.